ASTM B622 UNS N08031 Pipe, commonly known as Alloy 31 (1.4562), is a nickel-based alloy that offers excellent corrosion resistance in highly corrosive environments. It bridges the gap between super austenitic stainless steels and nickel-based alloys and is a cost-effective alternative. Contact us, Alloy 31 Suppliers, for more information and a free quote!
Alloy 31 Chemical Composition
- Nickel (Ni) 30.0–32.0
- Chromium (Cr) 26.0–28.0
- Molybdenum (Mo) 6.0–7.0
- Iron (Fe) Balance
- Nitrogen (N) 0.15–0.25
- Copper (Cu) 1.0–1.4
- Carbon (C) ≤0.015
Alloy 31 Corrosion Resistance
- To Oxidizing and Reducing Acids
- Sulfuric Acid: Very effective in concentrated sulfuric acid up to 60°C.
- Hydrochloric Acid: Moderate corrosion resistance, depending on concentration and temperature.
- Chloride Solutions: Excellent pitting and crevice corrosion protection.
Alloy 31 Mechanical Strength
- Tensile Strength ≥650 MPa
- Yield Strength (0.2% offset) ≥350 MPa
- Elongation (in 50mm) ≥35%
- Hardness (Brinell) ≤250 HB
Comparison with Similar Alloys
| Property | Alloy 31 | Alloy 625 | Alloy 904L |
|---|---|---|---|
| Corrosion Resistance | Excellent | Very High | High |
| Strength | High | Moderate | Moderate |
| Temperature Range | Up to 600°C | Up to 980°C | Up to 450°C |
| Cost Efficiency | High Value | Expensive | Cost-Effective |
Applications of ASTM B622 UNS N08031
- Chemical processing: Used in acid production plants, especially equipment for handling sulfuric and phosphoric acids
- Petrochemical industry: In refineries and natural gas plants
- Desalination plants
- Pollution control
- Flue gas desulfurization (FGD) systems
Temperature Range
- High temperature: Approximately 600°C (1112°F) for continuous use.
- Cryogenic : Maintains ductility and toughness even at very low temperatures.
UNS N08031 Fabrication and Welding
- Machinability: Requires carbide tools for effective machining.
- Weldability: Compatible with standard welding methods such as TIG, MIG, and SMAW.
Alloy Material Available Forms:
- Seamless pipe and tube
- Plate, sheet, and strip
- Bar, rod
- Fittings and flanges
